I doubt the Buddha actually meant only one specific posture, it seams strange considering he never mentions how to stand, walk, or laydown in instructions, he only mentions to use these postures.but just to note there is mention of how the Buddha lay down, walked... but to assume he was strict regarding posture when there are reasons not to adopt certain sitting postures seams to tight when it comes to here.

I doubt the Buddha actually meant only one specific posture, it seams strange considering he never mentions how to stand, walk, or laydown in instructions, he only mentions to use these postures.but just to note there is mention of how the Buddha lay down, walked... but to assume he was strict regarding posture when there are reasons not to adopt certain sitting postures seams to tight when it comes to here.

Actually just to contrast this with the precepts.With the precepts the Buddha is very clear as to what is meant, and expands, rewords, incorporates allowances... for the rules so they can be understood exactly what is meant. when a rule says don't wear jewellery, he means it, it isn't a case that he means exept in X, Y, or Z when he didn't say that. and the same is true elsewhere the Buddha says what he means sometimes a general principle can be applied, at another time a literal principle is meant.

so in essance you have to decide if it is a general or litteral principle that is needed to understand these things.

This offering maybe right, or wrong, but it is one, the other, both, or neither!Blog,-Some Suttas Translated,Ajahn Chah."Others will misconstrue reality due to their personal perspectives, doggedly holding onto and not easily discarding them; We shall not misconstrue reality due to our own personal perspectives, nor doggedly holding onto them, but will discard them easily. This effacement shall be done."

Another good occurrence of pallankam posture, meaning something rather firm and needed to be "split up" to release from. In the Mahāgosiṅga Sutta Buddha speaks about a monk determined to attain the final goal: